Phosphorus (P) is often limiting in agricultural soils, though it is required by plants for their growth and development. With the aim of reducing external P inputs, an array of microbial species able to live in association with plant roots, such as arbuscular mycorrhizal fungi (AMF), may be exploited to facilitate the optimization of phosphate use by plants in agroecosystems. To gain a better knowledge of fungal and plant traits possibly involved in P uptake and translocation, we studied the expression patterns of genes encoding phosphate transporters (PTs) in extraradical and intraradical mycelium (ERM and IRM), along with ERM extent and structure, plant growth and P uptake. Four maize inbred lines differing for their tolerance to low-P availability (Oh40B, Mo17, Oh43 and B73) were inoculated with Rhizoglomus irregulare and grown in a bidimensional experimental system in vivo. PT genes showed higher expression levels in ERM (and roots) of Mo17 (a low-P tolerant maize line) than in B73 (a low-P susceptible line), which also displayed a larger P increase in response to AMF colonization. Moreover, the ERM developing from roots of the B73 maize line was characterized by the highest hyphal density and interconnectedness. Interestingly, correlations were found between ERM structural traits, and both PT genes expression levels and plants mycorrhizal responsiveness. These results represent a sound basis for further studies aimed at unveiling the genetic mechanisms which regulate AMF symbiosis functioning, eventually allowing the design of “microbial management strategies” for a sustainable use of low-P tolerant crops.
Mycelial architecture and transcriptional changes of fungal phosphate transporters in mycorrhizal plants of different maize inbred lines
TURRINI A.
;AVIO L.;GIOVANNINI L.;GIOVANNETTI M.
2023-01-01
Abstract
Phosphorus (P) is often limiting in agricultural soils, though it is required by plants for their growth and development. With the aim of reducing external P inputs, an array of microbial species able to live in association with plant roots, such as arbuscular mycorrhizal fungi (AMF), may be exploited to facilitate the optimization of phosphate use by plants in agroecosystems. To gain a better knowledge of fungal and plant traits possibly involved in P uptake and translocation, we studied the expression patterns of genes encoding phosphate transporters (PTs) in extraradical and intraradical mycelium (ERM and IRM), along with ERM extent and structure, plant growth and P uptake. Four maize inbred lines differing for their tolerance to low-P availability (Oh40B, Mo17, Oh43 and B73) were inoculated with Rhizoglomus irregulare and grown in a bidimensional experimental system in vivo. PT genes showed higher expression levels in ERM (and roots) of Mo17 (a low-P tolerant maize line) than in B73 (a low-P susceptible line), which also displayed a larger P increase in response to AMF colonization. Moreover, the ERM developing from roots of the B73 maize line was characterized by the highest hyphal density and interconnectedness. Interestingly, correlations were found between ERM structural traits, and both PT genes expression levels and plants mycorrhizal responsiveness. These results represent a sound basis for further studies aimed at unveiling the genetic mechanisms which regulate AMF symbiosis functioning, eventually allowing the design of “microbial management strategies” for a sustainable use of low-P tolerant crops.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
